Я уже голову сломал, не понял как )=

Докажите, что прямая, содержащая середины двух параллельных хорд окружности, проходит через её центр.
Ребят,плз, желательно попонятнее и с рисунком (=

заполнить пропуски

печёночники. ПРИЗНАКИ ОТДЕЛА_________________,_______________.

ПРИЗНАКИ КЛАССА___________________,________________.

РОЛЬ В ПРИРОДЕ__________________,__________________

листостебельные .ПРИЗНАКИ ОТДЕЛА________,________.

ПРИЗНАКИ КЛАССА_________,________.

РОЛЬ В ПРИРОДЕ__________,__________.

напишите уравнение оси симметрии параболы y=x(в квадрате)+6x-3

Переведите текст и сделайте к тексту задания 

"I have just come from the sporting grounds and have carried away a sample1 of the earth there. All the three pieces are absolutely alike. Do you remember Soames said that one of the students, Gilford, was a jumper. Besides, he is the tallest of all the three. In short, the incident has become clear to me after my excursion. A long distance jumper is wearing sporting shoes during his exercise. Gilford was carrying them in his hand when he returned from the grounds. As he passed his teacher's window he could see from the outside that the examination papers were on the table. As the key was in the door he came in, put his shoes on the writing table and did not notice that a piece of earth from the shoes fell on the table. He began to copy the papers and was copying the second sheet when he suddenly heard the teacher at the door. There was no time to replace the papers. Where could he hide himself? Only in Mr. Soames' bedroom. He seized2 his shoes from the table and ran into the other room where again some earth fell on the floor. To his luck, Soames did not look behind the curtain where he was hiding, and he was not detected3.

"And now, Watson, let us go to Mr. Soames. I am sure he hasn't slept a minute since yesterday."

We found Mr. Soames in his room with an open letter in his hand.

"I've just received it," he said. "Fortunately this unhappy incident has been put an end to." He was going to read it to us at once, but Holmes stopped him.

"I know by whom it has been written," said Holmes. "I have found out the man and I am glad that he hasn't made use of hisdishonest8 action."

"You are quite right,"said Soames, "Gilford has told the truth. He is ashamed of himself and is going to leave college. He has been offered employment on board the ship and has accepted the offer. Let us hope that he will work there like an honest man."

а) Знайдіть у тексті й випишіть англійські еквіваленти таких словосполучень і речень.

спортивний майданчик, спортивні черевики, перекласти папери, на його щастя, нечесний вчинок, залишити iнститут, будемо сподiватися, чесна людина.

Він найбільш підозрілий. Що ви збираєтесь робити? Він ховався за занавіскою. Його не знайшли. Йому запропонували роботу.

б) запишiть англійською мовою, що трапилося після того, як: Холмс вранці повернувся додому;

Гілфорд зайшов до кімнати Сомса; Холмс і Ватсон зайшли до кімнати Сомса.

в) Знайдіть в оповіданні i запишiть пояснення доброго настрою Холмса.